Three small snacks
Two shakes or meal bars
One meal
The first thing you must ask yourself is if you can face having only one "real" meal each day. A shake or a bar isn't a meal, but a meal replacement. It's a bit of a shock to the system to go from eating three meals a day to drinking two of them.
Second, ask: Can you I do this long-term? Any sensible diet plan will lead you to lose no more than two pounds a week. (That's actually a good thing; losing any faster would be temporary, and possibly dangerous.) So, for example, if you have 40 pounds to lose that means you'll face at least five months of eating this way.
The next question you should ask yourself: Can you take the time and effort to plan nutritious meals and snacks? It is vital that your snacks and your daily meal are comprised of nutritous, healthful foods to ensure proper nutrition and health. You'll need to continue to buy a number of groceries in addition to the meal replacement shakes.
Lastly, you simply must ask yourself if you have the will power to stick to it. When you have consumed your shake, you probably won't "feel" as if you have eaten what you are used to consuming. It takes a lot of resolve not to reach for an off-plan food, especially if you are surrounded by other foods at work or at home. There isn't much point to drinking the shakes once or twice a day if you overeat the rest of the time.
On a personal note, I tried a popular liquid diet plan about 15 years ago after a celebrity touted its effectiveness. Things seemed to go well at first, but after a week or so, I began dreading my shakes so much that I was sometimes nauseated before drinking them. I began to feel weak and light headed even after eating the snacks I was allowed during the day. Things came to an abrupt halt when I blacked out at work one day. I vowed that would be the last liquid diet I tried, and I've kept that promise.
In the end, choosing among weight-loss methods is a personal decision that only you can make for yourself. Every diet plan has its own pros and cons. Some people actually like these types of diet plans because of convenience or simply not having to decide what to eat twice a day; others, like myself, see them as too extreme and difficult to adhere to. If you do decide to go on a liquid diet -- or any other restrictive diet plan -- please consult your doctor first.
